A search is underway to find the body of a man who went missing in the St. Croix River Monday night.

Search efforts began, according to the Pierce County Sheriff's Department, after a man was reported missing at around 10:40 p.m.

The man had entered the St. Croix River from the docks near the Steamboat Inn in Prescott. Authorities believe the man was either trying to swim across the river or to the highway bridge.

A second man then entered the water to attempt to either locate or rescue the first man. His attempts were unsuccessful and he safely returned to shore.

Search efforts continued through the night and into the early morning hours, but the sheriff's department says body recovery efforts are now underway. Several area law enforcement agencies are assisting in the effort.

Sheriff's department authorities say they are withholding the names or any information about either of the men until they can recover and then positively identify the body of the man they believe has drowned. They are also attempting to verify other information.

More on this story as additional information becomes available.